40 Questions
What is the primary focus of pharmacokinetics?
The mathematical description of the rate and extent of absorption, distribution, metabolism, and elimination of a drug
What is the primary route of elimination for most drugs?
Renal excretion
What is the term for the movement of a drug from the site of administration to the site of action?
Absorption
What is the term for the process by which a drug is broken down into its metabolites?
Biotransformation
What is the term for the study of the movement of drugs within the body, including absorption, distribution, metabolism, and elimination?
Pharmacokinetics
What is the characteristic of first-order elimination?
Rate of elimination is proportional to the concentration of the drug
What happens to the blood profile if the dose is increased twofold, assuming small dose apparent first-order kinetics?
The blood profile is increased according to curve C
What is the reason why F (bioavailability) is less than 1 for oral administration?
The drug is completely absorbed but some is metabolized in the liver
Which route of administration bypasses the hepatic portal vein system?
Intravenous administration
What is the term for the process by which a drug leaves the bloodstream and enters the tissues?
Distribution
What does the volume of distribution (Vd) represent?
The volume of body water where the drug is distributed
What is the unit of measurement for Cp(0)?
ug/ml
What is the formula to calculate the volume of distribution (Vd)?
Vd = dose / Cp(0)
What can be calculated from a graphical representation of drug distribution and elimination?
Both half-life and volume of distribution
What is the unit of measurement for the volume of distribution (Vd)?
L
What happens to the rate of elimination in a zero-order kinetics scenario?
It remains constant and is independent of drug concentration
What is observed in a drug that exhibits mixed elimination kinetics?
A combination of zero-order and first-order kinetics
What is the term for the time it takes for the plasma concentration of a drug to be reduced by half?
Half-life
What happens to the elimination mechanism at high concentrations of a drug?
It becomes zero-order kinetics
What is the shape of the curve obtained when a drug exhibits zero-order kinetics followed by first-order kinetics?
Curved with an initial slow phase followed by a rapid phase
What can be calculated from a graphical representation of drug elimination?
Half-life
What is the consequence of high plasma protein binding on a drug's volume of distribution?
It decreases the volume of distribution
In pharmacokinetic modeling, what is the assumption regarding the rate of elimination in first-order kinetics?
The rate of elimination is proportional to the concentration of the drug
What is the effect of lipophilicity on a drug's absorption and distribution?
Lipophilicity increases absorption and distribution
What is the consequence of a drug's hydrophilicity on its bioavailability?
It decreases the bioavailability
What is the primary reason behind Warfarin's low volume of distribution?
Reflects a high degree of plasma protein binding
What is the half-life of the drug in the given graphical representation?
2 hours
What is the characteristic of Chloroquine?
Highly-charged hydrophilic molecule
What is the correct formula to calculate the volume of distribution (Vd) from a given plasma concentration (Cp)?
Vd = dose / Cp
What is the volume of distribution (Vd) for a 70 kg man?
Unknown without additional information
What is the time dependence of drug vs. plasma concentration for drugs that distribute rapidly?
Instantaneous
What is the criteria for the FDA to consider two products bioequivalent?
Comparison of the test drug formulation to reference should be within 85% to 125%
What is the pharmacokinetic parameter used to compare two drugs with identical active ingredients?
All of the above
What is the absorption lag time (tlag) used to measure?
Delay between drug administration and the start of absorption
Which of the following drugs distributes slowly and cannot be described by a single exponential constant?
Benzodiazepines
What is the relationship between the half-life of a drug and its elimination rate constant?
Half-life is inversely proportional to the elimination rate constant
What happens to the rate of elimination in a zero-order kinetics scenario?
The rate of elimination is constant and independent of drug concentration
What is the shape of the curve obtained when a drug exhibits zero-order kinetics followed by first-order kinetics?
Biphasic with an initial slow elimination phase followed by a rapid elimination phase
What happens to the elimination mechanism at high concentrations of a drug?
The elimination mechanism becomes saturated
What is the characteristic of a drug that exhibits mixed elimination kinetics?
The drug exhibits zero-order kinetics at high concentrations and first-order kinetics at low concentrations
Test your knowledge of pharmacokinetics, covering topics such as drug metabolism, biotransformation, protein binding, and excretion. Understand how drugs interact with the body and how they are eliminated. Evaluate your understanding of pharmacokinetics and pharmacodynamics.
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